When should I prune my roses?
As a general rule of thumb, roses that flower only once in a season should be pruned right after flowering and roses that flower several times during the season should be pruned in late March or early April once the buds start to break (swell and green up): the adage is to prune your roses "when the forsythia blooms".
Once-blooming roses flower on old wood and continuous-blooming roses flower on new wood. Most Old Garden Roses flower only once; a few, such as 'Autumn Damask' and some Portlands, Hybrid Perpetuals, Bourbons, Chinas and Noisette roses tend to flower again. The majority of modern roses flower over a long period.
For detailed information on rose pruning technique and timing, please refer to our guide Pruning Roses. For more general information on pruning, the guides Pruning: An Introduction and Pruning Schedule for Shrubs may have what you are looking for.
Courtesy of the NYBG Plant Information Service